Channel arrangement method and radio communication base station device

ABSTRACT

Provided is a radio communication base station device which can prevent lowering of use efficiency of a channel communication resource for performing a frequency diversity transmission when simultaneously performing a frequency scheduling transmission and the frequency diversity transmission in a multicarrier communication. In the device, a modulation unit ( 12 ) executes a modulation process on Dch data after encoded so as to generate a Dch data symbol. A modulation unit ( 22 ) executes a modulation process on the encoded Lch data so as to generate an Lch data symbol. An allocation unit ( 103 ) allocates the Dch data symbol and the Lch data symbol to respective subcarriers constituting an OFDM symbol and outputs them to a multiplexing unit ( 104 ). Here, when a plurality of Dch are used for a Dch data symbol of one mobile station, the allocation unit ( 103 ) uses Dch of continuous channel numbers.

TECHNICAL FIELD

The present invention relates to a channel arrangement method and radiocommunication base station apparatus in multicarrier communications.

BACKGROUND ART

In recent years, various kinds of information apart from speech, such asimages and data, have come to be transmitted in radio communications,and particularly in mobile communications. With the demand for stillhigher-speed transmission expected to continue to grow in the future,there is a need for a radio transmission technology that achieves hightransmission efficiency through more efficient use of limited frequencyresources in order to perform high-speed transmission.

One radio transmission technology capable of meeting such a need is OFDM(Orthogonal Frequency Division Multiplexing). OFDM is a multicarriertransmission technology that performs parallel transmission of datausing a plurality of subcarriers, and is known for such features as highfrequency efficiency and reduced inter-symbol interference in amultipath environment, and for its effectiveness in improvingtransmission efficiency.

Studies have been carried out into performing frequency schedulingtransmission and frequency diversity transmission when this OFDM is usedin a downlink, and data for transmission to a plurality of radiocommunication mobile station apparatuses (hereinafter referred to simplyas mobile stations) is frequency-domain-multiplexed on a plurality ofsubcarriers.

In frequency scheduling transmission, a radio communication base stationapparatus (hereinafter referred to simply as a base station) allocatessubcarriers adaptively to mobile stations based on the received qualityof each frequency band at each mobile station, enabling a maximummulti-user diversity effect to be obtained, and extremely efficientcommunication to be performed. Such frequency scheduling transmission ismainly suitable for data communication when a mobile station is movingat low speed, or for high-speed data communication. On the other hand,frequency scheduling transmission requires feedback of received qualityinformation from each mobile station, and is therefore not suitable fordata communication when a mobile station is moving at high speed.Frequency scheduling transmission is normally performed in transmissiontime units called subframes for individual Resource Blocks (RBs) inwhich a number of adjacent subcarriers are collected together into ablock. A channel for performing this kind of frequency schedulingtransmission is called a Localized Channel (hereinafter referred to asLch).

In contrast, in frequency diversity transmission, data for each mobilestation is allocated distributed among subcarriers of an entire band,enabling a high frequency diversity effect to be obtained. Also,frequency diversity transmission does not require received qualityinformation from a mobile station, and is thus an effective method incircumstances in which use of frequency scheduling transmission isdifficult, as described above. On the other hand, frequency diversitytransmission is performed without regard to received quality at mobilestations, and therefore does not provide the kind of multi-userdiversity effect obtained with frequency scheduling transmission. Achannel for performing this kind of frequency diversity transmission iscalled a Distributed Channel (hereinafter referred to as Dch).

It is possible that frequency scheduling transmission in an Lch andfrequency diversity transmission in a Dch may be performedsimultaneously. That is to say, an RB used for an Lch and an RB used fora Dch may be frequency-domain-multiplexed on a plurality of subcarriersof one OFDM symbol. At this time, mapping between each RB and Lch, andmapping between each RB and Dch, are set in advance, and which RB isused as an Lch or a Dch is controlled in subframe units.

Another idea that has been studied is to further divide an RB used for aDch into a plurality of subblocks, and form one Dch by means of acombination of different RB subblocks. At this time, a plurality ofDch's with consecutive channel numbers are mapped to a plurality of RBsthat are consecutive in the frequency domain (see Non-Patent Document 1,for example).

Non-patent Document 1: R1-072431 “Comparison between RB-level andSub-carrier-level Distributed Transmission for Shared Data Channel inE-UTRA Downlink” 3GPP TSG RAN WG1 LTE Meeting, Kobe, Japan, 7-11 May,2007

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

Here, when a base station allocates a plurality of Dch's to one mobilestation, allocating a plurality of Dch's with consecutive channelnumbers can be considered. By this means, a mobile station can determinea Dch allocated to it by having only the first channel number and lastchannel number of consecutive channel numbers reported from the basestation to the mobile station. Thus, control information for reporting aDch allocation result can be reduced.

However, when a plurality of Dch's are allocated to one mobile station,it may be that, with a plurality of RBs in which Dch's with consecutivechannel numbers are arranged, only subblocks within RBs to which thoseDch's are allocated are used. Consequently, there is a possibility ofcommunication resource utilization efficiency falling because theremaining subblocks other than the used subblocks are not used.

For example, if 12 RBs #1 through #12 that are consecutive in thefrequency domain are each divided into two subblocks, and Dch #1 through#12 with consecutive channel numbers are mapped to RB #1 through #12,Dch #1 through #6 are mapped respectively to one subblock of RB #1through #6, and Dch #7 through #12 are mapped respectively to the othersubblock of RB #1 through #6. Similarly, Dch #1 through #6 are mappedrespectively to one subblock of RB #7 through #12, and Dch #7 through#12 are mapped respectively to the other subblock of RB #7 through #12.By this means, Dch #1 is formed by an RB #1 subblock and RB #7 subblock.The above explanation can be applied to Dch #2 through #12.

Here, if Dch #1 through #6 are allocated to one mobile station, only onesubblock corresponding to Dch #1 through #6 is used by RB #1 through#12, and the other subblock corresponding to Dch #7 through #12 is notused, with a resultant possibility of a fall in communication resourceutilization efficiency.

It is an object of the present invention to provide a channelarrangement method and base station that can prevent a fall inutilization efficiency of a channel communication resource forperforming frequency diversity transmission when simultaneouslyperforming frequency scheduling transmission and frequency diversitytransmission in multicarrier communication.

Means for Solving the Problem

A channel arrangement method of the present invention provides for aplurality of subcarriers forming a multicarrier signal to be dividedinto a plurality of resource blocks, and for a plurality of differentdistributed channels with consecutive channel numbers to be arranged inone resource block.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a fall in utilization efficiency ofa channel communication resource for performing frequency diversitytransmission can be prevented when simultaneously performing frequencyscheduling transmission and frequency diversity transmission inmulticarrier communication.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration of a base stationaccording to Embodiment 1 of the present invention;

FIG. 2 is a block diagram showing a configuration of a mobile stationaccording to Embodiment 1 of the present invention;

FIG. 3 shows an Lch arrangement method according to Embodiment 1 of thepresent invention;

FIG. 4 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 1: In case of division into two);

FIG. 5 shows an example of allocation according to Embodiment 1 of thepresent invention (Arrangement Method 1);

FIG. 6 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 1: In case of division intothree);

FIG. 7 is a drawing showing a block interleaver according to Embodiment1 of the present invention (Arrangement Method 2);

FIG. 8 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 2: In case of division into two);

FIG. 9 shows an example of allocation according to Embodiment 1 of thepresent invention (Arrangement Method 2);

FIG. 10 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 2: In case of division intothree);

FIG. 11 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 3: In case of division into two);

FIG. 12 shows an example of allocation according to Embodiment 1 of thepresent invention (Arrangement Method 3: Two Dch's);

FIG. 13 shows an example of allocation according to Embodiment 1 of thepresent invention (Arrangement Method 3: Four Dch's);

FIG. 14 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 3: In case of division intothree);

FIG. 15 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 4: In case of division into two);

FIG. 16 shows an example of allocation according to Embodiment 1 of thepresent invention (Arrangement Method 4: Four Dch's);

FIG. 17 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 4: In case of division intothree);

FIG. 18 shows a Dch arrangement method according to Embodiment 1 of thepresent invention (Arrangement Method 4: In case of division into four);

FIG. 19 shows a Dch arrangement method according to Embodiment 2 of thepresent invention (Switching Method 1);

FIG. 20 shows an example of allocation according to Embodiment 2 of thepresent invention (Switching Method 1);

FIG. 21 is a drawing showing a block interleaver according to Embodiment3 of the present invention;

FIG. 22 shows a Dch arrangement method according to Embodiment 3 of thepresent invention;

FIG. 23 shows an example of allocation according to Embodiment 3 of thepresent invention;

FIG. 24 is a drawing showing a block interleaver according to Embodiment5 of the present invention (when Nrb=12);

FIG. 25 is a drawing showing a block interleaver according to Embodiment5 of the present invention (when Nrb=14);

FIG. 26 shows a Dch arrangement method according to Embodiment 5 of thepresent invention (when Nrb=14); and

FIG. 27 is a flowchart showing block interleaver input/output processingaccording to Embodiment 5 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, embodiments of the present invention will be described in detailwith reference to the accompanying drawings.

Embodiment 1

The configuration of base station 100 according to this embodiment isshown in FIG. 1. Base station 100 divides a plurality of subcarrierscomprised of an OFDM symbol that is a multicarrier signal into aplurality of RBs, and uses a Dch and Lch on an RB-by-RB basis in thatplurality of RBs. Also, either a Dch or an Lch is allocated to onemobile station in the same subframe.

Base station 100 is equipped with n encoding and modulation sections101-1 through 101-n each comprising encoding section 11 and modulationsection 12 for Dch data, n encoding and modulation sections 102-1through 102-n each comprising encoding section 21 and modulation section22 for Lch data, and n demodulation and decoding sections 115-1 through115-n each comprising demodulation section 31 and decoding section 32,where n is a number of mobile stations (MSs) with which base station 100can communicate.

In encoding and modulation sections 101-1 through 101-n, encodingsection 11 performs turbo encoding or suchlike encoding processing onDch data #1 through #n of mobile stations #1 through #n, and modulationsection 12 performs modulation processing on post-encoding Dch data togenerate a Dch data symbol.

In encoding and modulation sections 102-1 through 102-n, encodingsection 21 performs turbo encoding or suchlike encoding processing onLch data #1 through #n of mobile stations #1 through #n, and modulationsection 22 performs modulation processing on post-encoding Lch data togenerate an Lch data symbol. The coding rate and modulation scheme usedat this time are in accordance with MCS (Modulation and Coding Scheme)information input from adaptive control section 116.

Allocation section 103 allocates a Dch data symbol and Lch data symbolto subcarriers comprised of an OFDM symbol in accordance with controlfrom adaptive control section 116, and performs output to multiplexingsection 104. At this time, allocation section 103 allocates a Dch datasymbol and Lch data symbol collectively on an RB-by-RB basis. Also, whenusing a plurality of Dch's for a Dch data symbol of one mobile station,allocation section 103 uses Dch's with consecutive channel numbers. Thatis to say, allocation section 103 allocates a plurality of differentDch's with consecutive channel numbers to a Dch data symbol of onemobile station. In each RB, Dch and Lch arrangement positions aremutually mapped in advance. That is to say, allocation section 103 holdsin advance an arrangement pattern constituting an association of a Dch,Lch, and RB, and allocates a Dch data symbol and Lch data symbol to eachRB in accordance with the arrangement pattern. Dch arrangement methodsaccording to this embodiment will be described in detail later herein.Allocation section 103 also outputs Dch data symbol allocationinformation (information indicating which mobile station's Dch datasymbol has been allocated to which RB) and Lch data symbol allocationinformation (information indicating which mobile station's Lch datasymbol has been allocated to which RB) to control information generationsection 105. For example, only the first channel number and last channelnumber of consecutive channel numbers are included in Dch data symbolallocation information.

Control information generation section 105 generates control informationcomprising Dch data symbol allocation information, Lch data symbolallocation information, and MCS information input from adaptive controlsection 116, and outputs this control information to encoding section106.

Encoding section 106 performs encoding processing on the controlinformation, and modulation section 107 performs modulation processingon the post-encoding control information and outputs the controlinformation to multiplexing section 104.

Multiplexing section 104 multiplexes control information with datasymbols input from allocation section 103, and outputs the resultingsignals to IFFT (Inverse Fast Fourier Transform) section 108. Controlinformation multiplexing is performed on a subframe-by-subframe basis,for example. In this embodiment, either time domain multiplexing orfrequency domain multiplexing may be used for control informationmultiplexing.

IFFT section 108 performs IFFT processing on a plurality of subcarrierscomprising a plurality of RBs to which control information and a datasymbol are allocated, to generate an OFDM symbol that is a multicarriersignal.

CP (Cyclic Prefix) adding section 109 adds a signal identical to the endpart of an OFDM symbol to the start of the OFDM symbol as a CP.

Radio transmission section 110 performs transmission processing such asD/A conversion, amplification, and up-conversion on a post-CP-additionOFDM symbol, and transmits it to each mobile station from antenna 111.

Meanwhile, radio reception section 112 receives n OFDM symbolstransmitted simultaneously from a maximum of n mobile stations viaantenna 111, and performs reception processing such as down-conversionand A/D conversion on these OFDM symbols.

CP removal section 113 removes a CP from a post-reception-processingOFDM symbol.

FFT (Fast Fourier Transform) section 114 performs FFT processing on apost-CP-removal OFDM symbol, to obtain per-mobile-station signalsmultiplexed in the frequency domain. Here, mobile stations transmitsignals using mutually different subcarriers or mutually different RBs,and per-mobile-station signals each include per-RB received qualityinformation reported from the respective mobile station. Each mobilestation can perform received quality measurement by means of a receivedSNR, received SIR, received SINR, received CINR, received power,interference power, bit error rate, throughput, an MCS that enables apredetermined error rate to be achieved, or the like. Received qualityinformation may be expressed as a CQI (Channel Quality Indicator), CSI(Channel State Information), or the like.

In demodulation and decoding sections 115-1 through 115-n, eachdemodulation section 31 performs demodulation processing on a post-FFTsignal, and each decoding section 32 performs decoding processing on apost-demodulation signal. By this means, received data is obtained.Received quality information within the received data is input toadaptive control section 116.

Adaptive control section 116 performs adaptive control on transmit datafor Lch data based on per-RB received quality information reported fromeach mobile station. That is to say, based on per-RB received qualityinformation, adaptive control section 116 performs selection of an MCScapable of satisfying a required error rate for encoding and modulationsections 102-1 through 102-n, and outputs MCS information. Also,adaptive control section 116 performs frequency scheduling that decidesfor allocation section 103 to which RB each of Lch data #1 through #n isallocated using a Max SIR method, Proportional Fairness method, orsuchlike scheduling algorithm. Furthermore, adaptive control section 116outputs per-RB MCS information to control information generation section105.

The configuration of mobile station 200 according to this embodiment isshown in FIG. 2. Mobile station 200 receives a multicarrier signal thatis an OFDM symbol comprising a plurality of subcarriers divided into aplurality of RBs from base station 100 (FIG. 1). In the plurality ofRBs, a Dch and Lch are used on an RB-by-RB basis. Also, in the samesubframe, either a Dch or Lch is allocated to mobile station 200.

In mobile station 200, radio reception section 202 receives an OFDMsymbol transmitted from base station 100 via antenna 201, and performsreception processing such as up-conversion and A/D conversion on theOFDM symbol.

CP removal section 203 removes a CP from a post-reception-processingOFDM symbol.

FFT section 204 performs FFT processing on a post-CP-removal OFDMsymbol, to obtain a received signal in which control information and adata symbol are multiplexed.

Demultiplexing section 205 demultiplexes a post-FFT received signal intoa control signal and data symbol. Then demultiplexing section 205outputs the control signal to demodulation and decoding section 206, andoutputs the data symbol to demapping section 207.

In demodulation and decoding section 206, demodulation section 41performs demodulation processing on the control signal, and decodingsection 42 performs decoding processing on the post-demodulation signal.Here, control information includes Dch data symbol allocationinformation, Lch data symbol allocation information, and MCSinformation. Then demodulation and decoding section 206 outputs Dch datasymbol allocation information and Lch data symbol allocation informationwithin the control information to demapping section 207.

Based on allocation information input from demodulation and decodingsection 206, demapping section 207 extracts a data symbol allocated tothat station from a plurality of RBs to which a data symbol input fromdemultiplexing section 205 has been allocated. In the same way as basestation 100 (FIG. 1), Dch and Lch arrangement positions are mutuallymapped in advance for each RB. That is to say, demapping section 207holds in advance the same arrangement pattern as allocation section 103of base station 100, and extracts a Dch data symbol and Lch data symbolfrom a plurality of RBs in accordance with the arrangement pattern.Also, as described above, when allocation section 103 of base station100 (FIG. 1) uses a plurality of Dch's for a Dch data symbol of onemobile station, Dch's with consecutive channel numbers are used. Also,only the first channel number and last channel number of consecutivechannel numbers are indicated in allocation information included incontrol information from base station 100. Thus, demapping section 207identifies a Dch used in a Dch data symbol allocated to that stationbased on the first channel number and last channel number indicated inthe allocation information. Then demapping section 207 extracts an RBmapped to the channel number of an identified Dch, and outputs a datasymbol allocated to the extracted RB to demodulation and decodingsection 208.

In demodulation and decoding section 208, demodulation section 51performs demodulation processing on a data symbol input from demappingsection 207, and decoding section 52 performs decoding processing on thepost-demodulation signal. By this means, received data is obtained.

Meanwhile, in encoding and modulation section 209, encoding section 61performs turbo encoding or suchlike encoding processing on transmissiondata, and modulation section 62 performs modulation processing onpost-encoding transmission data to generate a data symbol. Here, mobilestation 200 transmits transmission data using different subcarriers ordifferent RBs from other mobile stations, and per-RB received qualityinformation is included in the transmission data.

IFFT section 210 performs IFFT processing on a plurality of subcarrierscomprising a plurality of RBs to which a data symbol input from encodingand modulation section 209 is allocated, to generate an OFDM symbol thatis a multicarrier signal.

CP adding section 211 adds a signal identical to the end part of an OFDMsymbol to the start of the OFDM symbol as a CP.

Radio transmission section 212 performs transmission processing such asD/A conversion, amplification, and up-conversion on a post-CP-additionOFDM symbol, and transmits it to base station 100 (FIG. 1) from antenna201.

Next, Dch channel arrangement methods according to this embodiment willbe described. In the following description, a case in which a pluralityof subcarriers comprised of one OFDM symbol are divided equally among 12RBs—RB #1 through #12—will be taken as an example. Also, Lch #1 through#12 and Dch #1 through #12 are formed by respective RBs, and a channelused by each mobile station is controlled by adaptive control section116. The Lch configuration for RBs shown in FIG. 3 and the Dchconfiguration for RBs shown below are mutually assigned in advance byallocation section 103.

Here, frequency scheduling for Lch's is performed in RB units, andtherefore an Lch data symbol for one mobile station only is included ineach RB used for an Lch. That is to say, one Lch for one mobile stationis formed by one RB. Therefore, Lch #1 through #12 are arranged by meansof RB #1 through #12 as shown in FIG. 3. That is to say, the allocationunit of each Lch is “1 RB×1 subframe.”

On the other hand, frequency diversity transmission is performed forDch's, and therefore a plurality of Dch data symbols are included in anRB used for a Dch. Here, each RB used for a Dch is time-divided into twosubblocks, and a different Dch is arranged in each subblock. That is tosay, a plurality of different Dch's are time-domain-multiplexed in oneRB. Also, one Dch is formed by two different RB subblocks. That is tosay, the allocation unit of each Dch is “(1 RB×½ subframe)×2,” the sameas the allocation unit of each Lch.

<Arrangement Method 1 (FIG. 4)>

With this arrangement method, Dch's with consecutive channel numbers arearranged in one RB.

First, a relational expression for a Dch channel number and the RBnumber of an RB in which that Dch is arranged will be shown.

When the number of subblock divisions per RB is Nd, RB number j of an RBin which Dch #(Nd·(k−1)+1), Dch #(Nd·(k−1)+2), . . . , Dch #(Nd·k) withconsecutive channel numbers are arranged is given by Equation (1) below.

[1]

j=k+floor(Nrb/Nd)·p, p=0, 1, . . . , Nd−1  (Equation 1)

where k=1, 2, . . . , floor(Nrb/Nd), operator floor(x) represents thelargest integer that does not exceed x, and Nrb is the number of RBs.Here, floor(Nrb/Nd) is the RB interval at which the same Dch isarranged.

That is to say, quantity Nd of Dch's comprising Dch #(Nd·(k−1)+1), Dch#(Nd·(k−1)+2), . . . , Dch #(Nd·k) that are arranged in the same RB andhave consecutive channel numbers are distributively arranged in quantityNd of RBs, RB#(j), separated by a floor(Nrb/Nd) RB interval, in thefrequency domain.

Here, since Nrb=12 and Nd=2, above Equation (1) gives j=k+6·p (p=0, 1),where k=1, 2, . . . , 6. Thus, two Dch's with consecutive channelnumbers, Dch #(2k−1) and Dch #(2k), are distributively arranged in twoRBs, RB #(k) and RB #(k+6), separated by a 6 (= 12/2) RB interval in thefrequency domain.

Specifically, as shown in FIG. 4, Dch #1 and #2 are arranged in RB #1(RB #7), Dch #3 and #4 are arranged in RB #2 (RB #8), Dch #5 and #6 arearranged in RB #3 (RB #9), Dch #7 and #8 are arranged in RB #4 (RB #10),Dch #9 and #10 are arranged in RB #5 (RB #11), and Dch #11 and #12 arearranged in RB #6 (RB #12).

An example of allocation by allocation section 103 of base station 100(FIG. 1) when four Dch's, Dch #1 through #4, are used for a Dch datasymbol of one mobile station is shown in FIG. 5. Here, allocationsection 103 holds the Dch arrangement pattern shown in FIG. 4, andallocates a Dch data symbol to RBs in accordance with the arrangementpattern shown in FIG. 4.

As shown in FIG. 5, allocation section 103 allocates a Dch data symbolto an RB #1 subblock and RB #7 subblock forming Dch #1, an RB #1subblock and RB #7 subblock forming Dch #2, an RB #2 subblock and RB #8subblock forming Dch #3, and an RB #2 subblock and RB #8 subblockforming Dch #4. That is to say, as shown in FIG. 5, a Dch data symbol isallocated to RB #1, #2, #7, #8.

Also, as shown in FIG. 5, allocation section 103 allocates an Lch datasymbol to remaining RB #3 through #6 and RB #9 through #12 other thanthe RBs to which a Dch data symbol has been allocated. That is to say,Lch #3 through #6 and Lch #9 through #12 shown in FIG. 3 are used for anLch data symbol.

Next, an example of extraction by demapping section 207 of mobilestation 200 (FIG. 2) will be described for a case in which a Dch datasymbol using four consecutive Dch's, Dch #1 through #4, is allocated tomobile station 200. Here, demapping section 207 holds the Dcharrangement pattern shown in FIG. 4, the same as allocation section 103,and extracts a Dch data symbol from a plurality of RBs in accordancewith the arrangement pattern shown in FIG. 4. First channel number Dch#1 and last channel number Dch #4 are indicated in Dch data symbolallocation information reported to mobile station 200 from base station100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #4, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the four consecutive Dch's Dch #1 through #4. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 formed by an RB #1 subblock and RB #7subblock, Dch #2 formed by an RB #1 subblock and RB #7 subblock, Dch #3formed by an RB #2 subblock and RB #8 subblock, and Dch #4 formed by anRB #2 subblock and RB #8 subblock, as shown in FIG. 5. That is to say,demapping section 207 extracts a Dch data symbol allocated to RB #1, #2,#7, #8, as shown in FIG. 5, as a data symbol addressed to that station.

Thus, with this arrangement method, Dch's with consecutive channelnumbers are arranged in one RB, and therefore when one mobile stationuses a plurality of Dch's, all the subblocks of one RB are used, andthen subblocks of another RB are used. By this means, it is possible tominimize the allocation of a data symbol to some subblocks among aplurality of subblocks forming one RB while other subblocks are notused. Therefore, according to this arrangement method, a fall in theresource utilization efficiency of a channel for performing frequencydiversity transmission can be prevented when simultaneously performingfrequency scheduling transmission in an Lch and frequency diversitytransmission in a Dch. Also, according to this arrangement method, afall in the utilization efficiency of an RB communication resource usedfor a Dch can be prevented, increasing the number of RBs that can beused for Lch's, and enabling frequency scheduling to be performed formore frequency bands.

Also, according to this arrangement method, when one mobile station usesa plurality of Dch's, a plurality of Dch's with consecutive channelnumbers are arranged in RBs that are consecutive in the frequencydomain. Consequently, RBs that can be used for Lch's—that is, remainingRBs other than RBs used by a Dch—are also consecutive in terms offrequency. For example, when frequency selectivity of a channel ismoderate or when the bandwidth of each RB is narrow, RB bandwidthbecomes narrow with respect to a frequency selective fading correlationbandwidth. At this time, RBs with good channel quality are consecutivein a frequency band with high channel quality. Therefore, when RBbandwidth becomes narrow with respect to a frequency selective fadingcorrelation bandwidth, use of this arrangement method enables RBs thatare consecutive in the frequency domain to be used for Lch's, enabling afrequency scheduling effect to be further improved.

Furthermore, according to this arrangement method, a plurality of Lch'swith consecutive channel numbers can be allocated. Consequently, when abase station allocates a plurality of Lch's to one mobile station, it issufficient for only the first channel number and last channel number ofconsecutive channel numbers to be reported to a mobile station from thebase station. Therefore, control information for reporting an Lchallocation result can be reduced in the same way as when a Dchallocation result is reported.

With this arrangement method, a case has been described in which one RBis divided into two when using Dch's, but the number of divisions of oneRB is not limited to two, and one RB may also be divided into three ormore divisions. For example, an allocation method for a case in whichone RB is divided into three when using Dch's is shown in FIG. 6. Asshown in FIG. 6, three consecutive Dch's are arranged in one RB,enabling the same kind of effect to be obtained as with this arrangementmethod. Also, since one Dch is formed by distribution among three RBs asshown in FIG. 6, a diversity effect can be improved to a greater extentthan in the case of division into two.

<Arrangement Method 2 (FIG. 8)>

With this arrangement method, the fact that a plurality of differentDch's with consecutive channel numbers are arranged in one RB is thesame as in Arrangement Method 1, but a difference from ArrangementMethod 1 is that a lowest-numbered or highest-numbered Dch and a Dchwith a consecutive channel number among the plurality of Dch's arearranged in the above-described one RB and RBs distributively arrangedin the frequency domain.

With this arrangement method, as with Arrangement Method 1 (FIG. 4),Dch's with consecutive channel numbers are arranged in the same RB. Thatis to say, of Dch #1 through #12 shown in FIG. 8, (Dch #1, #2), (Dch #3,#4), (Dch #5, #6), (Dch #7, #8), (Dch #9, #10), and (Dch #11, #12) areDch combinations each formed by the same RB.

Of the above plurality of combinations, combinations in which alowest-numbered or highest-numbered Dch included in one combination anda Dch with a consecutive channel number are included are arranged in RBsdistributed in the frequency domain. That is to say, (Dch #1, #2) and(Dch #3, #4) in which Dch #2 and Dch #3 with consecutive channel numbersare respectively included are arranged in different distributed RBs,(Dch #3, #4) and (Dch #5, #6) in which Dch #4 and Dch #5 withconsecutive channel numbers are respectively included are arranged indifferent distributed RBs, (Dch #5, #6) and (Dch #7, #8) in which Dch #6and Dch #7 with consecutive channel numbers are respectively includedare arranged in different distributed RBs, (Dch #7, #8) and (Dch #9,#10) in which Dch #8 and Dch #9 with consecutive channel numbers arerespectively included are arranged in different distributed RBs, and(Dch #9, #10) and (Dch #11, #12) in which Dch #10 and Dch #11 withconsecutive channel numbers are respectively included are arranged indifferent distributed RBs.

Here, as with Arrangement Method 1, a relational expression for a Dchchannel number and the RB number of an RB in which that Dch is arrangedwill be shown.

RB number j of an RB in which Dch #(Nd·(k−1)+1), Dch #(Nd·(k−1)+2), . .. , Dch #(Nd·k) with consecutive channel numbers included in combinationk are arranged is given by Equation (2) below.

[2]

j=q(k)+floor(Nrb/Nd)·p, p=0, 1, . . . , Nd−1  (Equation 2)

where q(k) is given by a 2-row×(floor(Nrb/Nd)/2)-column blockinterleaver. The number of rows of the block interleaver has beenassumed to be 2, but may be any positive integer less than or equal tofloor(Nrb/Nd). By this means, combination k and a combination in which alowest-numbered or highest-numbered Dch included in combination k and aDch with a consecutive channel number (combination k−1 or combinationk+1) are arranged in distributed RBs with different RB numbers.

Here, since Nrb=12 and Nd=2, above Equation (2) gives j=q(k)+6·p (p=0,1), where q(k) is given by a 2-row×3-column block interleaver as shownin FIG. 7. That is to say, as shown in FIG. 7, q(k)=1, 4, 2, 5, 3, 6 isobtained for k=1, 2, 3, 4, 5, 6. Thus, two Dch's with consecutivechannel numbers, Dch #(2k−1) and Dch #(2k), are distributively arrangedin two RBs, RB #(q(k)) and RB #(q(k)+6), separated by a 6 (= 12/2) RBinterval in the frequency domain.

Specifically, for example, as shown in FIG. 8, Dch #1 and #2 arearranged in RB #1 (RB #7), Dch #5 and #6 are arranged in RB #2 (RB #8),Dch #9 and #10 are arranged in RB #3 (RB #9), Dch #3 and #4 are arrangedin RB #4 (RB #10), Dch #7 and #8 are arranged in RB #5 (RB #11), and Dch#11 and #12 are arranged in RB #6 (RB #12).

As with Arrangement Method 1, an example of allocation by allocationsection 103 of base station 100 (FIG. 1) when four consecutive Dch's,Dch #1 through #4, are used for a Dch data symbol of one mobile stationis shown in FIG. 9. Here, allocation section 103 holds the Dcharrangement pattern shown in FIG. 8, and allocates a Dch data symbol toRBs in accordance with the arrangement pattern shown in FIG. 8.

As shown in FIG. 9, allocation section 103 allocates a Dch data symbolto an RB #1 subblock and RB #7 subblock forming Dch #1, an RB #1subblock and RB #7 subblock forming Dch #2, an RB #4 subblock and RB #10subblock forming Dch #3, and an RB #4 subblock and RB #10 subblockforming Dch #4. That is to say, as shown in FIG. 9, a Dch data symbol isallocated to RB #1, #4, #7, #10.

Also, as shown in FIG. 9, allocation section 103 allocates an Lch datasymbol to remaining RB #2, #3, #5, #6, #8, #9, #11, #12 other than theRBs to which a Dch data symbol has been allocated. That is to say, Lch#2, #3, #5, #6, #8, #9, #11, #12 shown in FIG. 3 are used for an Lchdata symbol.

Next, as with Arrangement Method 1, an example of extraction bydemapping section 207 of mobile station 200 (FIG. 2) will be describedfor a case in which a Dch data symbol using four consecutive Dch's, Dch#1 through #4, is allocated to mobile station 200. Here, demappingsection 207 holds the Dch arrangement pattern shown in FIG. 8, the sameas allocation section 103, and extracts a Dch data symbol from aplurality of RBs in accordance with the arrangement pattern shown inFIG. 8. As with Arrangement Method 1, first channel number Dch #1 andlast channel number Dch #4 are indicated in Dch data symbol allocationinformation reported to mobile station 200 from base station 100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #4, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the four consecutive Dch's Dch #1 through #4. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 formed by an RB #1 subblock and RB #7subblock, Dch #2 formed by an RB #1 subblock and RB #7 subblock, Dch #3formed by an RB #4 subblock and RB #10 subblock, and Dch #4 formed by anRB #4 subblock and RB #10 subblock, as shown in FIG. 9. That is to say,demapping section 207 extracts a Dch data symbol allocated to RB #1, #4,#7, #10, as shown in FIG. 9, as a data symbol addressed to that station.

With this arrangement method, as with Arrangement Method 1, a Dch datasymbol is allocated to four RBs, and an Lch data symbol is allocated toeight RBs. However, with this arrangement method, a Dch data symbol isdistributively allocated every three RBs, to RB #1, RB #4, RB #7, and RB#10, as shown in FIG. 9, enabling a frequency diversity effect to beimproved to a greater extent than with Arrangement Method 1 (FIG. 5).Also, as shown in FIG. 9, having a Dch data symbol allocated todistributed RBs also means that an Lch data symbol is distributed,making it possible to perform frequency scheduling using RBs across awider band.

Thus, with this arrangement method, a lowest-numbered orhighest-numbered Dch and a Dch with a consecutive channel number among aplurality of different Dch's are arranged in one RB in which theplurality of different Dch's with consecutive channel numbers arearranged and RBs distributed in the frequency domain. Consequently, evenif a plurality of Dch's are used for a data symbol of one mobilestation, it is possible to prevent non-use of some RB subblocks, andallocate a data symbol distributed across a wide band. Therefore,according to this arrangement method, the same kind of effect can beobtained as with Arrangement Method 1, and furthermore, a frequencydiversity effect can be improved. Also, with this arrangement method,RBs used for Dch's are distributed, enabling remaining RBs other thanRBs used for Dch's—that is, RBs used for Lch's—to be distributed aswell. As a result, according to this arrangement method a frequencyscheduling effect can be improved.

With this arrangement method, a case has been described in which one RBis divided into two when using Dch's, but the number of divisions of oneRB is not limited to two, and one RB may also be divided into three ormore divisions. For example, an allocation method for a case in whichone RB is divided into three when using Dch's is shown in FIG. 10. Asshown in FIG. 10, different RBs including consecutive Dch's aredistributed in the frequency domain, enabling the same kind of effect tobe obtained as with this arrangement method. Also, since one Dch isformed by distribution among three RBs as shown in FIG. 10, a diversityeffect can be improved to a greater extent than in the case of divisioninto two.

<Arrangement Method 3 (FIG. 11)>

With this arrangement method, Dch's with consecutive channel numbers arearranged in different RBs, and Dch's with channel numbers within apredetermined number are arranged in one RB.

This is described in concrete terms below. Here, the predeterminednumber is assumed to be 2. That is to say, the difference in channelnumbers of mutually different Dch's included in the same RB does notexceed 2.

First, a relational expression for a Dch channel number and the RBnumber of an RB in which that Dch is arranged will be shown.

RB number j of an RB in which mutually different Dch's included incombination k are arranged is given by Equation (2), in the same way aswith Arrangement Method 2. However, whereas with Arrangement Method 2Dch channel numbers included in combination k are consecutive, with thisarrangement method Dch channel numbers included in combination k areseparated by a predetermined number. Also, combination number k isassigned a smaller value for a combination of Dch's with smaller channelnumbers.

Here, since Nrb=12 and Nd=2, j=q(k)+6·p (p=0, 1) in the same way as withArrangement Method 2, where q(k) is given by the 2-row×3-column blockinterleaver shown in FIG. 7, also as with Arrangement Method 2. Thus,Dch's included in combination k are distributively arranged in two RBs,RB #(q(k)) and RB #(q(k)+6), separated by a 6 (= 12/2) RB interval inthe frequency domain. However, since the predetermined number is 2,combination 1 (k=1) becomes (Dch #1, #3) and combination 2 (k=2) becomes(Dch #2, #4). The above explanation can be applied to combinations 3through 6.

Therefore, as shown in FIG. 11, Dch #1 and #3 are arranged in RB #1 (RB#7), Dch #5 and #7 are arranged in RB #2 (RB #8), Dch #9 and #11 arearranged in RB #3 (RB #9), Dch #2 and #4 are arranged in RB #4 (RB #10),Dch #6 and #8 are arranged in RB #5 (RB #11), and Dch #10 and #12 arearranged in RB #6 (RB #12).

An example of allocation by allocation section 103 of base station 100(FIG. 1) when two consecutive Dch's, Dch #1 and #2, are used for a Dchdata symbol of one mobile station—that is, when the number of Dch's usedfor a Dch data symbol of one mobile station is small—is shown in FIG.12. Here, allocation section 103 holds the Dch arrangement pattern shownin FIG. 11, and allocates a Dch data symbol to RBs in accordance withthe arrangement pattern shown in FIG. 11.

As shown in FIG. 12, allocation section 103 allocates a Dch data symbolto an RB #1 subblock and RB #7 subblock forming Dch #1, and an RB #4subblock and RB #10 subblock forming Dch #2. That is to say, as shown inFIG. 12, a Dch data symbol is allocated to RB #1, #4, #7, #10distributed in the frequency domain.

Next, an example of extraction by demapping section 207 of mobilestation 200 (FIG. 2) will be described for a case in which a Dch datasymbol using two consecutive Dch's, Dch #1 and #2, is allocated tomobile station 200. Here, demapping section 207 holds the Dcharrangement pattern shown in FIG. 11, the same as allocation section103, and extracts a Dch data symbol from a plurality of RBs inaccordance with the arrangement pattern shown in FIG. 11. First channelnumber Dch #1 and last channel number Dch #2 are indicated in Dch datasymbol allocation information reported to mobile station 200 from basestation 100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #2, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the two consecutive Dch's Dch #1 and #2. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 formed by an RB #1 subblock and RB #7subblock, and Dch #2 formed by an RB #4 subblock and RB #10 subblock, asshown in FIG. 12. That is to say, demapping section 207 extracts a Dchdata symbol allocated to RB #1, #4, #7, #10 distributed in the frequencydomain, as shown in FIG. 12, as a data symbol addressed to that station.

Thus, when the number of Dch's used for a Dch data symbol of one mobilestation is small—that is, when there are few allocated RBs—the effect ofa fall in communication resource utilization efficiency for the entireband is small. Therefore, a frequency diversity effect can be obtainedpreferentially even though there is a possibility of subblocks otherthan subblocks allocated within RBs not being used.

On the other hand, an example of allocation by allocation section 103 ofbase station 100 (FIG. 1) when four consecutive Dch's, Dch #1 through#4, are used for a Dch data symbol of one mobile station—that is, whenthe number of Dch's used for a Dch data symbol of one mobile station islarge—is shown in FIG. 13. Here, allocation section 103 holds the Dcharrangement pattern shown in FIG. 11, and allocates a Dch data symbol toRBs in accordance with the arrangement pattern shown in FIG. 11.

As shown in FIG. 13, allocation section 103 allocates a Dch data symbolto an RB #1 subblock and RB #7 subblock forming Dch #1, an RB #4subblock and RB #10 subblock forming Dch #2, an RB #1 subblock and RB #7subblock forming Dch #3, and an RB #4 subblock and RB #10 subblockforming Dch #4. That is to say, as shown in FIG. 13, a Dch data symbolis allocated to RB #1, #4, #7, #10, distributed in the frequency domain,in the same way as in FIG. 12. Also, in FIG. 13, a Dch data symbol isallocated to all the subblocks of RB #1, #4, #7, #10.

Next, an example of extraction by demapping section 207 of mobilestation 200 (FIG. 2) will be described for a case in which a Dch datasymbol using four consecutive Dch's, Dch #1 through #4, is allocated tomobile station 200. Here, demapping section 207 holds the Dcharrangement pattern shown in FIG. 11, the same as allocation section103, and extracts a Dch data symbol from a plurality of RBs inaccordance with the arrangement pattern shown in FIG. 11. First channelnumber Dch #1 and last channel number Dch #4 are indicated in Dch datasymbol allocation information reported to mobile station 200 from basestation 100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #4, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the four consecutive Dch's Dch #1 through #4. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 formed by an RB #1 subblock and RB #7subblock, Dch #2 formed by an RB #4 subblock and RB #10 subblock, Dch #3formed by an RB #1 subblock and RB #7 subblock, and Dch #4 formed by anRB #4 subblock and RB #10 subblock, as shown in FIG. 13. That is to say,demapping section 207 extracts a Dch data symbol allocated to all thesubblocks of RB #1, #4, #7, #10, as shown in FIG. 13, as a data symboladdressed to that station.

Thus, even when the number of Dch's used for a Dch data symbol of onemobile station is large—that is, when there are many allocated RBs—allsubblocks within RBs can be used while obtaining a frequency diversityeffect.

Thus, with this arrangement method, Dch's with consecutive channelnumbers are arranged in different RBs, and Dch's with channel numberswithin a predetermined number are arranged in one RB. By this means, afrequency diversity effect can be improved when the number of Dch's usedfor a Dch data symbol of one mobile station is small. Also, even whenthe number of Dch's used for a Dch data symbol of one mobile station islarge, a frequency diversity effect can be improved without loweringcommunication resource utilization efficiency.

With this arrangement method, a case has been described in which one RBis divided into two when using Dch's, but the number of divisions of oneRB is not limited to two, and one RB may also be divided into three ormore divisions. For example, an allocation method for a case in whichone RB is divided into three when using Dch's is shown in FIG. 14. Asshown in FIG. 14, Dch's with consecutive channel numbers are arranged indifferent RBs, and Dch's with channel numbers within a predeterminednumber of 2 are arranged in one RB, enabling the same kind of effect tobe obtained as with this arrangement method. Also, since one Dch isformed by distribution among three RBs as shown in FIG. 14, a diversityeffect can be improved to a greater extent than in the case of divisioninto two.

<Arrangement Method 4 (FIG. 15)>

With this arrangement method, the fact that a plurality of differentDch's with consecutive channel numbers are arranged in one RB is thesame as in Arrangement Method 1, but a difference from ArrangementMethod 1 is that RBs in which the same Dch is arranged are allocated inorder from both ends of a band.

With this arrangement method, as with Arrangement Method 1 (FIG. 4),Dch's with consecutive channel numbers are arranged in the same RB. Thatis to say, of Dch #1 through #12 shown in FIG. 15, (Dch #1, #2), (Dch#3, #4), (Dch #5, #6), (Dch #7, #8), (Dch #9, #10), and (Dch #11, #12)are Dch combinations each formed by the same RB.

Two RBs in which Dch's of the above combinations are arranged areallocated in order from both ends of a band. That is to say, as shown inFIG. 15, combination (Dch #1, #2) is arranged in RB #1 and RB #12, andcombination (Dch #3, #4) is arranged in RB #2 and RB #11. Similarly,(Dch #5, #6) is arranged in RB #3 and RB #10, (Dch #7, #8) is arrangedin RB #4 and RB #9, (Dch #9, #10) is arranged in RB #5 and RB #8, and(Dch #11, #12) is arranged in RB #6 and RB #7.

As with Arrangement Method 1, an example of allocation by allocationsection 103 of base station 100 (FIG. 1) when four consecutive Dch's,Dch #1 through #4, are used for a Dch data symbol of one mobile stationis shown in FIG. 16. Here, allocation section 103 holds the Dcharrangement pattern shown in FIG. 15, and allocates a Dch data symbol toRBs in accordance with the arrangement pattern shown in FIG. 15.

As shown in FIG. 16, allocation section 103 allocates a Dch data symbolto an RB #1 subblock and RB #12 subblock forming Dch #1, an RB #1subblock and RB #12 subblock forming Dch #2, an RB #2 subblock and RB#11 subblock forming Dch #3, and an RB #2 subblock and RB #11 subblockforming Dch #4. That is to say, as shown in FIG. 16, a Dch data symbolis allocated to RB #1, #2, #11, #12.

Also, as shown in FIG. 16, allocation section 103 allocates an Lch datasymbol to remaining RB #3, #4, #5, #6, #7, #8, #9, #10 other than theRBs to which a Dch data symbol has been allocated. That is to say, Lch#3, #4, #5, #6, #7, #8, #9, #10 shown in FIG. 3 are used for an Lch datasymbol.

Next, as with Arrangement Method 1, an example of extraction bydemapping section 207 of mobile station 200 (FIG. 2) will be describedfor a case in which a Dch data symbol using four consecutive Dch's, Dch#1 through #4, is allocated to mobile station 200. Here, demappingsection 207 holds the Dch arrangement pattern shown in FIG. 15, the sameas allocation section 103, and extracts a Dch data symbol from aplurality of RBs in accordance with the arrangement pattern shown inFIG. 15. As with Arrangement Method 1, first channel number Dch #1 andlast channel number Dch #4 are indicated in Dch data symbol allocationinformation reported to mobile station 200 from base station 100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #4, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the four consecutive Dch's Dch #1 through #4. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 formed by an RB #1 subblock and RB #12subblock, Dch #2 formed by an RB #1 subblock and RB #12 subblock, Dch #3formed by an RB #2 subblock and RB #11 subblock, and Dch #4 formed by anRB #2 subblock and RB #11 subblock, as shown in FIG. 16. That is to say,demapping section 207 extracts a Dch data symbol allocated to RB #1, #2,#11, #12 as shown in FIG. 16, as a data symbol addressed to thatstation.

With this arrangement method, as with Arrangement Method 1 andArrangement Method 2, a Dch data symbol is allocated to four RBs, and anLch data symbol is allocated to eight RBs. However, with thisarrangement method, a Dch data symbol is allocated to RBs at both endsof a band, as shown in FIG. 16. Since the RB interval at which a Dchdata symbol is allocated is wider than in the case of Arrangement Method1 (FIG. 5) or Arrangement Method 2 (FIG. 9), a frequency diversityeffect can be improved. Also, as shown in FIG. 16, having a Dch datasymbol allocated to RBs at both ends of a band also means that an Lchdata symbol is distributed, making it possible to perform frequencyscheduling using RBs across a wider band.

Also, according to this arrangement method, RBs that can be used forLch's—that is, remaining RBs other than RBs used by a Dch—are allconsecutive in terms of frequency. For example, when frequencyselectivity of a channel is moderate or when the bandwidth of each RB isnarrow, RB bandwidth becomes narrow with respect to a frequencyselective fading correlation bandwidth. At this time, RBs with goodchannel quality are consecutive in a frequency band with high channelquality. Therefore, when RB bandwidth becomes narrow with respect to afrequency selective fading correlation bandwidth, use of thisarrangement method enables RBs that are consecutive in the frequencydomain to be used for Lch's, enabling a frequency scheduling effect tobe further improved.

Furthermore, according to this arrangement method, a plurality of Lch'swith consecutive channel numbers can be allocated. Consequently, when abase station allocates a plurality of Lch's to one mobile station, it issufficient for only the first channel number and last channel number ofconsecutive channel numbers to be reported to a mobile station from thebase station. With this arrangement method, all RBs that can be used forLch's are consecutive in the frequency domain, and consequently evenwhen all Lch's are allocated to one mobile station, enabling abovereporting method to be used. Therefore, control information forreporting an Lch allocation result can be reduced in the same way aswhen a Dch allocation result is reported.

With this arrangement method, a case has been described in which one RBis divided into two when using Dch's, but the number of divisions of oneRB is not limited to two, and one RB may also be divided into three ormore divisions. For example, allocation methods for cases in which oneRB is divided into three and into four when using Dch's are shown inFIG. 17 and FIG. 18 respectively. As shown in FIG. 17 and FIG. 18,different RBs including consecutive Dch's are arranged preferentiallyfrom both ends of a band, enabling the same kind of effect to beobtained as with this arrangement method. Also, since one Dch is formedby distribution among three RBs or four RBs as shown in FIG. 17 and FIG.18 respectively, a diversity effect can be improved to a greater extentthan in the case of division into two.

This concludes a description of Arrangement Methods 1 through 4according to this embodiment.

Thus, according to this embodiment, a fall in the communication resourceutilization efficiency of a channel for performing frequency diversitytransmission can be prevented when simultaneously performing frequencyscheduling transmission in an Lch and frequency diversity transmissionin a Dch. Also, according to this embodiment, a fall in the utilizationefficiency of an RB used for a Dch can be prevented, increasing thenumber of RBs that can be used for Lch's, and enabling frequencyscheduling to be performed for more frequency bands.

Embodiment 2

In this embodiment a case will be described in which switching betweenuse of Arrangement Method 1 and Arrangement Method 2 of Embodiment 1 isperformed according to the communication environment.

As described above, Arrangement Method 1 enables more RBs consecutive inthe frequency domain that can be used for Lch's to be secured thanArrangement Method 2, while Arrangement Method 2 has a greater frequencydiversity effect than Arrangement Method 1.

Specifically, when four consecutive Dch's, Dch #1 through #4, are usedfor a Dch data symbol of one mobile station, with Arrangement Method 1(FIG. 5) four RBs consecutive in the frequency domain, RB #3 through #6and RB #9 through #12, can be used for an Lch, while a Dch data symbolis allocated to two RBs consecutive in the frequency domain, RB #1, #2and RB #7, #8. On the other hand, with Arrangement Method 2 (FIG. 9)only two RBs consecutive in the frequency domain, RB #2, #3, RB #5, #6,RB #8, #9, and RB #11, #12, can be used for an Lch, while a Dch datasymbol is distributively allocated every three RBs, to RB #1, #4, #7,#10.

Thus, with Arrangement Method 1 and Arrangement Method 2, there is atrade-off between a frequency diversity effect and the number of RBsconsecutive in the frequency domain that can be used for Lch's.

Allocation section 103 according to this embodiment (FIG. 1) switchesbetween Arrangement Method 1 and Arrangement Method 2 of Embodiment 1according to the communication environment, and allocates a Dch datasymbol and Lch data symbol to an RB respectively.

Next, Switching Methods 1 through 3 used by allocation section 103 ofthis embodiment will be described.

<Switching Method 1>

With this switching method, the arrangement method is switched accordingto the number of subblock divisions per RB. In the followingdescription, the number of subblock divisions per RB is indicated by Nd.

The larger the value of Nd, the larger is the number of different RBs inwhich the same Dch is arranged. For example, with Arrangement Method 1,when Nd=2 the same Dch is distributively arranged in two different RBsas shown in FIG. 4, whereas when Nd=4 the same Dch is distributivelyarranged in four different RBs as shown in FIG. 19. Thus, the larger thevalue of Nd, the larger is the number of different RBs in which the sameDch is distributively arranged, and therefore the greater is thefrequency diversity effect. In other words, the smaller the value of Nd,the smaller is the frequency diversity effect.

At the same time, the smaller the value of Nd, the larger is thefrequency interval between different RBs in which the same Dch isarranged. For example, with Arrangement Method 1, when Nd=2 thefrequency interval of subblocks forming the same Dch is six RBs as shownin FIG. 4, whereas when Nd=4 the frequency interval of subblocks formingthe same Dch is three RBs. Thus, the smaller the value of Nd, the largeris the frequency interval of subblocks forming the same Dch, andcorrespondingly more RBs consecutive in terms of frequency can besecured for Lch's. In other words, the larger the value of Nd, thesmaller is the number of RBs consecutive in the frequency domain thatcan be used for Lch's.

Thus, allocation section 103 allocates Dch's using Arrangement Method 1when the value of Nd is large—that is, when the number of RBsconsecutive in the frequency domain that can be used for Lch's issmall—and allocates Dch's using Arrangement Method 2 when the value ofNd is small—that is, when the frequency diversity effect is small.Specifically, allocation section 103 performs arrangement methodswitching based on a comparison between Nd and a preset threshold value.That is to say, allocation section 103 switches to Arrangement Method 1when Nd is greater than or equal to the threshold value, and switches toArrangement Method 2 when Nd is less than the threshold value.

As in Embodiment 1, an example of allocation when four consecutiveDch's, Dch #1 through #4, are used for a Dch data symbol of one mobilestation is shown in FIG. 20. Here, a case in which Nd=4 (when the numberof divisions is large), and a case in which Nd=2 (when the number ofdivisions is small), will be described when the preset threshold valueis 3. When Nd=2, the situation is the same as with Arrangement Method 2of Embodiment 1 (FIG. 9), and therefore a description thereof is omittedhere. When Nd=4, as shown in FIG. 20, allocation section 103 allocates aDch data symbol to an RB #1 subblock, RB #4 subblock, RB #7 subblock,and RB #10 subblock forming Dch #1, an RB #1 subblock, RB #4 subblock,RB #7 subblock, and RB #10 subblock forming Dch #2, an RB #1 subblock,RB #4 subblock, RB #7 subblock, and RB #10 subblock forming Dch #3, andan RB #1 subblock, RB #4 subblock, RB #7 subblock, and RB #10 subblockforming Dch #4, in accordance with Arrangement Method 1 (FIG. 19). Thatis to say, as shown in FIG. 20, a Dch data symbol is allocated to RB #1,#4, #7, #10.

Also, as shown in FIG. 20, allocation section 103 allocates an Lch datasymbol to remaining RB #2, #3, #5, #6, #8, #9, #11, #12 other than theRBs to which a Dch data symbol has been allocated. That is to say, Lch#2, #3, #5, #6, #8, #9, #11, #12 shown in FIG. 3 are used for an Lchdata symbol.

Thus, with this switching method, both when Nd=4 (FIG. 20) and when Nd=2(FIG. 9), a Dch data symbol is allocated to RB #1, RB #4, RB #7, and RB#10, and an Lch data symbol is allocated to RB #2, #3, #5, #6, #8, #9,#11, #12.

That is to say, when the value of Nd is large (when the number of RBsconsecutive in the frequency domain that can be used for Lch's issmall), using Arrangement Method 1 enables the number of RBs consecutivein the frequency domain that can be used for Lch's to be maximized whileobtaining a frequency diversity effect. On the other hand, when thevalue of Nd is small (when the frequency diversity effect is small),using Arrangement Method 2 enables the frequency diversity effect to beimproved while securing RBs consecutive in the frequency domain that canbe used for Lch's.

Thus, according to this switching method, when the number of subblockdivisions per RB is large, switching is performed to an arrangementmethod whereby RBs consecutive in the frequency domain that can be usedfor Lch's are obtained preferentially, whereas when the number ofsubblock divisions per RB is small, switching is performed to anarrangement method whereby a frequency diversity effect is obtainedpreferentially. By this means, in both cases regarding the number ofsubblock divisions per RB, a frequency diversity effect and a frequencyscheduling effect can both be improved. Also, according to thisswitching method, Lch's used in frequency scheduling transmission aresecured in RBs that are consecutive in the frequency domain, enablingcontrol information for reporting an Lch allocation result to bereduced.

Also, according to this switching method, the larger the number ofmobile stations or the number of Dch's, the larger is the value of Ndthat may be used. Consequently, when the number of mobile stations orthe number of a plurality of mutually different Dch's is larger, thesame Dch is allocated to a larger number of different RBs, enabling afrequency diversity effect for one Dch to be further improved. On theother hand, when the number of mobile stations or the number of aplurality of mutually different Dch's is smaller, the number of aplurality of mutually different Dch's per RB decreases, enabling theoccurrence of vacancies occurring in some per-RB subblocks to beprevented, and enabling a fall in communication resource utilizationefficiency to be prevented. For example, when Nd=4, vacancies occur insome subblocks of one RB when the number of a plurality of mutuallydifferent Dch's is less than four. However, making the value of Nd lessthan 4 results in a higher possibility of all of a plurality ofsubblocks included in one RB being used, enabling a fall incommunication resource utilization efficiency to be prevented.

<Switching Method 2>

With this switching method, the arrangement method is switched accordingto a channel state, such as channel frequency selectivity, for example.

When frequency selectivity is moderate, RBs with high channel qualitytend to be consecutive in the frequency domain, making this situationsuitable for frequency scheduling transmission. On the other hand, whenfrequency selectivity is significant, RBs with high channel quality tendto be distributed in the frequency domain, making this situationsuitable for frequency diversity transmission.

Thus, allocation section 103 allocates Dch's using Arrangement Method 1when frequency selectivity is moderate, and allocates Dch's usingArrangement Method 2 when frequency selectivity is significant.

When frequency selectivity is moderate (when RBs with high channelquality are consecutive in the frequency domain), using ArrangementMethod 1 enables RBs consecutive in the frequency domain to be used forLch's, enabling a frequency scheduling effect to be improved. Also,since Lch's are secured in RBs that are consecutive in the frequencydomain, control information for reporting an Lch allocation result canbe reduced.

On the other hand, when frequency selectivity is significant (when RBswith high channel quality are distributed in the frequency domain),using Arrangement Method 2 results in Lch's being distributivelyallocated in the frequency domain, enabling frequency scheduling to beperformed using RBs with high channel quality that are distributedacross a wide band.

Thus, according to this switching method, arrangement method switchingis performed according to frequency selectivity, and therefore whateverthe frequency selectivity situation, a frequency scheduling effect forLch's can be improved while obtaining a frequency diversity effect forDch's.

Frequency selectivity used in this switching method can be measured bymeans of channel delay dispersion (delayed wave spread), for example.

Also, since frequency selectivity differs according to cell size andcell conditions, this switching method may be applied on a cell-by-cellbasis, and the arrangement method may be switched on a cell-by-cellbasis. Furthermore, since frequency selectivity also differs for eachmobile station, this switching method may be applied on an individualmobile station basis.

<Switching Method 3>

With this switching method, the arrangement method is switched accordingto system bandwidth—that is, a bandwidth in which RBs are allocated.

The narrower the system bandwidth, the smaller is the frequency intervalbetween RBs used for Dch's. Consequently, a frequency diversity effectis not improved however many Dch's are distributively arranged in thefrequency domain.

On the other hand, the wider the system bandwidth, the larger is thefrequency interval between RBs used for Dch's. Consequently, when aplurality of Dch's are distributively arranged in the frequency domain,a large number of RBs consecutive in the frequency domain, proportionalto the frequency interval between RBs used for Dch's, can be secured forLch's, enabling a frequency scheduling effect to be obtained.

Thus, allocation section 103 allocates Dch's using Arrangement Method 1when system bandwidth is narrow, and allocates Dch's using ArrangementMethod 2 when system bandwidth is wide.

In this way, when system bandwidth is narrow, using Arrangement Method 1enables RBs consecutive in the frequency domain that can be used forLch's to be secured preferentially, rather than obtaining a frequencydiversity effect. On the other hand, when system bandwidth is wide,using Arrangement Method 2 enables a frequency diversity effect to beimproved without impairing a frequency scheduling effect.

Thus, according to this switching method, the arrangement method isswitched according to system bandwidth, and therefore an optimalfrequency scheduling effect can always be obtained whatever the systembandwidth. Also, since Lch's are secured in RBs that are consecutive inthe frequency domain, control information for reporting an Lchallocation result can be reduced.

This concludes a description of Switching Methods 1 through 3 used byallocation section 103 of this embodiment.

Thus, according to this embodiment, switching between Dch arrangementmethods is performed according to the communication environment,enabling Lch frequency scheduling transmission and Dch frequencydiversity transmission to be performed optimally at all times accordingto the communication environment.

In this embodiment, cases have been described in which arrangementmethod switching is performed by allocation section 103 (FIG. 1), butarrangement method switching need not be performed by allocation section103. For example, an arrangement method switching section (not shown)may perform arrangement method switching according to the communicationenvironment, and issue an arrangement method directive to allocationsection 103.

Also, in this embodiment, cases have been described in which allocationsection 103 (FIG. 1) switches between Arrangement Method 1 andArrangement Method 2, but allocation section 103 can obtain the samekind of effect as described above, and the effect explained in thedescription of Arrangement Method 3 of Embodiment 1, by usingArrangement Method 3 of Embodiment 1 instead of Arrangement Method 2.Allocation section 103 may also switch among Arrangement Methods 1through 3 according to the communication environment.

Furthermore, in this embodiment, when performing arrangement methodswitching, relational expressions Equation (1) and Equation (2) showinga relationship between a Dch channel number and the RB number of an RBin which that Dch is arranged, or a relational expression variable suchas q(k), may be switched. Also, in this embodiment, these relationalexpression variables may be reported to a mobile station. By this means,a mobile station can switch to an appropriate arrangement method eachtime arrangement method switching is performed, and can thus determine aDch allocated to it.

Embodiment 3

In this embodiment a case will be described in which only one Dch isarranged in one RB (the number of subblock divisions per RB is one).

First, a relational expression for a Dch channel number and the RBnumber of an RB in which that Dch is arranged will be shown.

RB number j of an RB in which a Dch with channel number k is arranged isgiven by Equation (3) below.

[3]

j=q(k)  (Equation 3)

where k=1, 2, . . . , Nrb, and q(k) is given by an M-row×(Nrb/M)-columnblock interleaver where M is an arbitrary positive integer.

If it is assumed here that Nrb=12 and M=4, q(k) is given by the4-row×3-column block interleaver shown in FIG. 21. That is to say, asshown in FIG. 21, q(k)=1, 7, 4, 10, 2, 8, 5, 11, 3, 9, 6, 12 is obtainedfor k=1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. Thus, Dch #(k) isdistributively arranged in RB #(q(k)).

Specifically, as shown in FIG. 22, Dch #1 is arranged in RB #1, Dch #5is arranged in RB #2, Dch #9 is arranged in RB #3, Dch #3 is arranged inRB #4, Dch #7 is arranged in RB #5, Dch #11 is arranged in RB #6, Dch #2is arranged in RB #7, Dch #6 is arranged in RB #8, Dch #10 is arrangedin RB #9, Dch #4 is arranged in RB #10, Dch #8 is arranged in RB #11,and Dch #12 is arranged in RB #12.

Thus, when using Lch's (FIG. 3), Lch #1 through #12 with consecutivechannel numbers are arranged in order in RB #1 through #12, whereas whenusing Dch's (FIG. 22), Dch's with consecutive channel numbers arearranged in RBs that are distributively arranged in terms of frequency.That is to say, different channel numbers are set for each RB of RB #1through #12 when Lch's are used and when Dch's are used.

As in Embodiment 1, an example of allocation by allocation section 103of base station 100 (FIG. 1) when four consecutive Dch's, Dch #1 through#4, are used for a Dch data symbol of one mobile station is shown inFIG. 23. Here, allocation section 103 holds the Dch arrangement patternshown in FIG. 22, and allocates a Dch data symbol to RBs in accordancewith the arrangement pattern shown in FIG. 22.

As shown in FIG. 23, allocation section 103 allocates a Dch data symbolto RB #1 in which Dch #1 is arranged, RB #7 in which Dch #2 is arranged,RB #4 in which Dch #3 is arranged, and RB #10 in which Dch #4 isarranged. That is to say, as shown in FIG. 23, a Dch data symbol isallocated to RB #1, #4, #7, #10.

Also, as shown in FIG. 23, allocation section 103 allocates an Lch datasymbol to remaining RB #2, #3, #5, #6, #8, #9, #11, #12 other than theRBs to which a Dch data symbol has been allocated. That is to say, Lch#2, #3, #5, #6, #8, #9, #11, #12 shown in FIG. 3 are used for an Lchdata symbol.

Next, as in Embodiment 1, an example of extraction by demapping section207 of mobile station 200 (FIG. 2) will be described for a case in whicha Dch data symbol using four consecutive Dch's, Dch #1 through #4, isallocated to mobile station 200. Here, demapping section 207 holds theDch arrangement pattern shown in FIG. 22, the same as allocation section103, and extracts a Dch data symbol from a plurality of RBs inaccordance with the arrangement pattern shown in FIG. 22. First channelnumber Dch #1 and last channel number Dch #4 are indicated in Dch datasymbol allocation information reported to mobile station 200 from basestation 100.

Since the Dch channel numbers indicated in the Dch data symbolallocation information are Dch #1 and Dch #4, demapping section 207identifies the fact that Dch's used for a Dch data symbol addressed tothat station are the four consecutive Dch's Dch #1 through #4. Then,following a similar procedure to allocation section 103, demappingsection 207 extracts Dch #1 arranged in RB #1, Dch #2 arranged in RB #7,Dch #3 arranged in RB #4, and Dch #4 arranged in RB #10, as shown inFIG. 23. That is to say, demapping section 207 extracts a Dch datasymbol allocated to RB #1, #4, #7, #10, as shown in FIG. 23, as a datasymbol addressed to that station.

In this embodiment, as with Arrangement Methods 1 through 3 ofEmbodiment 1, a Dch data symbol is allocated to four RBs, and an Lchdata symbol is allocated to eight RBs. Also, in this embodiment, a Dchdata symbol is distributively allocated every three RBs, to RB #1, RB#4, RB #7, and RB #10, as shown in FIG. 23, enabling a frequencydiversity effect to be improved. Furthermore, as shown in FIG. 23,having a Dch data symbol allocated to distributively arranged RBs alsomeans that an Lch data symbol is distributed, making it possible toperform frequency scheduling using RBs across a wider band.

Thus, in this embodiment, only one Dch is arranged in one RB, and aplurality of different Dch's with consecutive channel numbers arearranged in RBs that are distributively arranged in the frequencydomain. By this means, when a plurality of Dch's are allocated to onemobile station, non-use of some RBs is completely eliminated, and afrequency diversity effect can be obtained.

Also, according to this embodiment, Dch's with consecutive channelnumbers are arranged in RBs that are distributively arranged in thefrequency domain, but Dch channel numbers and RB numbers are mutuallymapped in advance, enabling control information for reporting a Dchallocation result to be reduced in the same way as in Embodiment 1.

Embodiment 4

In this embodiment a case will be described in which switching betweenuse of Arrangement Method 1 and Arrangement Method 4 of Embodiment 1 isperformed according to per-RB number of subblock divisions Nd.

As described above, Arrangement Method 4 enables more RBs consecutive inthe frequency domain that can be used for Lch's to be secured thanArrangement Method 1.

On the other hand, when a large number of Dch's are used, withArrangement Method 4 the interval between RBs in which Dch's arearranged differs greatly according to the Dch, and therefore a frequencydiversity effect due to Dch's is non-uniform. Specifically, in FIG. 15Dch #1 is arranged in RB #1 and #12, and therefore the RB interval is 11RBs and a large frequency diversity effect is obtained, but Dch #12 isarranged in RB #6 and #7, and therefore the RB interval is 1 and thefrequency diversity effect is small.

On the other hand, with Arrangement Method 1 the interval between RBs inwhich one Dch is arranged is uniform, enabling a uniform frequencydiversity effect to be obtained irrespective of the Dch.

Also, as stated above (paragraph [0117]), by using a larger value of Ndthe larger the number of mobile stations or the number of Dch's used, afrequency diversity effect can be further improved while preventing afall in communication resource utilization efficiency.

Thus, in this embodiment, allocation section 103 allocates Dch's usingArrangement Method 1 when the value of Nd is large—that is, when moreDch's are allocated—and allocates Dch's using Arrangement Method 4 whenthe value of Nd is small—that is, when fewer Dch's are allocated.Specifically, allocation section 103 performs arrangement methodswitching based on a comparison between Nd and a preset threshold value.That is to say, allocation section 103 switches to Arrangement Method 1when Nd is greater than or equal to the threshold value, and switches toArrangement Method 4 when Nd is less than the threshold value.

For example, the Dch arrangement shown in FIG. 15 is used when Nd=2, andthe kind of arrangement shown in FIG. 19 is used when Nd=4.

By this means, a frequency diversity effect can be improved whether thenumber of Dch's is large or small. That is to say, when the value of Ndis large (when the number of Dch's is large), an arrangement is adoptedthat allows uniformly good frequency diversity to be obtained for allDch's, and when the value of Nd is small (when the number of Dch's issmall), an arrangement is adopted that enables a frequency diversityeffect to be improved for a specific Dch. Here, when the number of Dch'sis small, nonuniformity of a frequency diversity effect with ArrangementMethod 4 is not a problem if Dch's in the vicinity of both ends of theband (that is, low-numbered Dch's in FIG. 15) are used preferentially.

Using Arrangement Method 4 when the value of Nd is small (when thenumber of Dch's is small) enables more consecutive Lch RBs to besecured, and enables a consecutive RB allocation reporting method to beused for more Lch's. When the number of mobile stations is small, onemobile station often occupies a large number of RBs when communicating,and there is consequently a large communication efficiency improvementeffect. Using Arrangement Method 1 when the value of Nd is large (whenthe number of Dch's is large) enables more distributed Lch RBs to besecured. When the number of mobile stations is large, the moredistributed Lch's are for use of resources by a plurality of mobilestations, the greater is a frequency scheduling effect, and consequentlythe more communication efficiency improves.

Since the ratio between the number of mobile stations using Dch's andthe number of mobile stations using Lch's is generally constantirrespective of the total number of mobile stations, this embodiment iseffective.

Thus, according to this embodiment, a good frequency diversity effect isobtained irrespective of the number of mobile stations, andcommunication efficiency can be improved.

Embodiment 5

In this embodiment, the fact that Dch's with consecutive channel numbersare arranged in different RBs and Dch's with channel numbers within apredetermined number are arranged in one RB is the same as inArrangement Method 3 of Embodiment 1, but Dch's are arranged using adifferent block interleaver from that in Arrangement Method 3 ofEmbodiment 1.

This is described in concrete terms below. Here, as with ArrangementMethod 3 of Embodiment 1, it is assumed that Nrb=12, Nd=2, and thepredetermined number is 2. Also, Lch #1 through #12 or Dch #1 through#12 are formed by means of RBs.

In this embodiment, Dch channel numbers are given by the 3-row×4-columnblock interleaver shown in FIG. 24. Specifically, Dch channel numbersk=1, 2, . . . , Nrb are input to the block interleaver shown in FIG. 24,and Dch channel numbers j (k) are output. That is to say, Dch channelnumbers are rearranged by the block interleaver shown in FIG. 24. Then,if k<floor(Nrb/Nd), the RB numbers of RBs in which Dch #(j(k)) isarranged become RB #(k) and RB #(k+floor(Nrb/Nd)). On the other hand, ifk>floor(Nrb/Nd), the RB numbers of RBs in which Dch #(j(k)) is arrangedbecome RB #(k) and RB #(k-floor(Nrb/Nd)). Here, floor(Nrb/Nd) representsan interval between RBs in which one Dch is arranged.

Here, since Nrb=12 and Nd=2, floor(Nrb/Nd)=6. Also, as regards j(k),j(k)=1, 5, 9, 2, 6, 10, 3, 7, 11, 4, 8, 12 is obtained for k=1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, as shown in FIG. 24. Thus, when k<6, Dch#(j(k)) is distributively arranged in two RBs, RB #(k) and RB #(k+6),separated by a 6 (=floor( 12/2)) RB interval in the frequency domain,and when k>6, Dch #(j(k)) is distributively arranged in two RBs, RB #(k)and RB #(k−6), separated by a 6 RB interval in the frequency domain.

Specifically, when k=1, j(k)=1, and therefore Dch #1 is distributivelyarranged in RB #1 and RB #7 (=1+6), and when k=2, j(k)=5, and thereforeDch #5 is distributively arranged in RB #2 and RB #8 (=2+6). The aboveexplanation can be applied when k=3 through 6.

Also, when k=7, j(k)=3, and therefore Dch #3 is distributively arrangedin RB #7 and RB #1 (=7-6), and when k=8, j(k)=7, and therefore Dch #7 isdistributively arranged in RB #8 and RB #2 (=8-6). The above explanationcan be applied when k=9 through 12.

By this means, as shown in FIG. 11, Dch #1 and #3 are arranged in RB #1(RB #7), Dch #5 and #7 are arranged in RB #2 (RB #8), Dch #9 and #11 arearranged in RB #3 (RB #9), Dch #2 and #4 are arranged in RB #4 (RB #10),Dch #6 and #8 are arranged in RB #5 (RB #11), and Dch #10 and #12 arearranged in RB #6 (RB #12), in the same way as in Arrangement Method 3of Embodiment 1. That is to say, Dch's with consecutive channel numbersare arranged in different RBs, and Dch's with channel numbers within apredetermined number (here, 2) are arranged in one RB. Thus, the samekind of effect as in Arrangement Method 3 of Embodiment 1 can also beobtained when Dch channel numbers are interleaved using the blockinterleaver shown in FIG. 24.

Here, channel numbers j(k)=1, 5, 9, 2, 6, and 10 of the first half ofthe block interleaver output shown in FIG. 24 (that is, the first andsecond columns of the block interleaver), and channel numbers j(k)=3, 7,11, 4, 8, and 12 of the second half of the block interleaver outputshown in FIG. 24 (that is, the third and fourth columns of the blockinterleaver), are arranged in the same RBs as shown in FIG. 11. That isto say, channel numbers located at the same position in the3-row×2-column first half of the block interleaver shown in FIG. 24comprising the first and second columns, and the 3-row×2-column secondhalf of the block interleaver shown in FIG. 24 comprising the third andfourth columns, have a correspondence relationship of being arranged inthe same RBs. For example, channel number 1 located in the first columnof the first row of the first half (the first column of the first row ofthe block interleaver shown in FIG. 24), and channel number 3 located inthe first column of the first row of the second half (the third columnof the first row of the block interleaver shown in FIG. 24), arearranged in the same RBs (RB #1 and #7 shown in FIG. 11). Similarly,channel number 5 located in the first column of the second row of thefirst half (the first column of the second row of the block interleavershown in FIG. 24), and channel number 7 located in the first column ofthe second row of the second half (the third column of the second row ofthe block interleaver shown in FIG. 24), are arranged in the same RBs(RB #2 and #8 shown in FIG. 11). The above explanation can be applied toother positions.

Also, channel numbers located at the same position in the first half andsecond half of the block interleaver output are channel numbersseparated by (number of columns/Nd). Therefore, by making the number ofcolumns of the block interleaver 4, as shown in FIG. 24, Dch's withchannel numbers separated by only two channel numbers are arranged inthe same RB. That is to say, Dch's with channel numbers within apredetermined number (number of columns/Nd) are arranged in the same RB.In other words, the difference between channel numbers of Dch's arrangedin one RB can be kept within a predetermined number by making the numberof columns of a block interleaver [predetermined number×Nd].

Next, a channel arrangement method will be described for a case in whichthe number of Dch channels (corresponding here to number of RBs Nrb) isnot divisible by the number of columns of the block interleaver.

This is described in concrete terms below. It is assumed here thatNrb=14, Nd=2, and the predetermined number is 2. Also, Lch #1 through#14 or Dch #1 through #14 are formed by means of RBs. Since Nd=2 and thepredetermined number is 2, the number of columns of the blockinterleaver is 4. Thus, with regard to the block interleaver size, thenumber of columns is fixed at 4, and the number of rows is calculated asceil(Nrb/number of columns), where operator ceil(x) represents thesmallest integer that exceeds x. That is to say, a 4 (=ceil(14/4))-row×4-column block interleaver such as shown in FIG. 25 is usedhere.

While the size of the block interleaver shown in FIG. 25 is 16 (=4rows×4 columns), Dch channel numbers k=1, 2, . . . , Nrb that are inputto the block interleaver are only 14 in number. That is to say, thenumber of Dch channels is smaller than the size of the blockinterleaver, and the number of Dch channels (14) is not divisible by thenumber of columns of the block interleaver (4).

Thus, in this embodiment, a number of Nulls equivalent to the differencebetween the size of the block interleaver and the number of Dch channelsare inserted in the block interleaver. That is to say, two (=16−14)Nulls are inserted in the block interleaver as shown in FIG. 25.Specifically, two Nulls are inserted uniformly in the last fourth-row ofthe block interleaver. In other words, two Nulls are inserted at everyother position in the last fourth-row of the block interleaver. That isto say, as shown in FIG. 25, Nulls are inserted in the second column andfourth column of the fourth row within the 4-row×4-column blockinterleaver. Thus, as shown in FIG. 25, Dch channel numbers k=1 through14 are input in the column direction at positions other than those ofthe Nulls in the second column and fourth column of the last fourth-row.That is to say, in the last row of the block interleaver, Dch channelnumbers k=13 and 14 are inserted at every other position in the columndirection. When Nd=2, two mutually different Dch's are distributivelyarranged in each subblock of two RBs, and therefore the total number ofDch channels is an even number. Consequently, only cases in which thenumber of Nulls inserted in a block interleaver in which the number ofcolumns is 4 is 0 or 2 are possible.

Here, since Nrb=14 and Nd=2, floor(Nrb/Nd)=7. Also, j (k) is given by a4-row×4-column block interleaver as shown in FIG. 25. The Nulls insertedin the block interleaver shown in FIG. 25 are skipped when blockinterleaver output is performed, and are not output as j(k). That is tosay, j(k)=1, 5, 9, 13, 2, 6, 10, 3, 7, 11, 14, 4, 8, 12 is obtained fork=1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, as shown in FIG. 25.Thus, when k<7, Dch #(j(k)) is distributively arranged in two RBs, RB#(k) and RB #(k+7), separated by a 7 (=floor( 14/2)) RB interval in thefrequency domain, and when k>7, Dch #(j(k)) is distributively arrangedin two RBs, RB #(k) and RB #(k−7), separated by a 7 RB interval in thefrequency domain.

Specifically, when k=1, j(k)=1, and therefore Dch #1 is distributivelyarranged in RB #1 and RB #8 (=1+7), and when k=2, j(k)=5, and thereforeDch #5 is distributively arranged in RB #2 and RB #9 (=2+7). The aboveexplanation can be applied when k=3 through 7.

Also, when k=8, j(k)=3, and therefore Dch #3 is distributively arrangedin RB #8 and RB #1 (=8−7), and when k=9, j(k)=7, and therefore Dch #7 isdistributively arranged in RB #9 and RB #2 (=9-7). The above explanationcan be applied when k=10 through 14.

By this means, as shown in FIG. 26, Dch #1 and #3 are arranged in RB #1(RB #8), Dch #5 and #7 are arranged in RB #2 (RB #9), Dch #9 and #11 arearranged in RB #3 (RB #10), Dch #13 and #14 are arranged in RB #4 (RB#11), Dch #2 and #4 are arranged in RB #5 (RB #12), Dch #6 and #8 arearranged in RB #6 (RB #13), and Dch #10 and #12 are arranged in RB #7(RB #14). That is to say, two Dch's with channel numbers withinpredetermined number 2 are arranged in all RBs, as shown in FIG. 26.

Similarly to the case of the block interleaver shown in FIG. 24, channelnumbers j(k)=1, 5, 9, 13, 2, 6, and 10 of the first half of the blockinterleaver output shown in FIG. 25 (that is, the first and secondcolumns of the block interleaver), and channel numbers j(k)=3, 7, 11,14, 4, 8, and 12 of the second half of the block interleaver output(that is, the third and fourth columns of the block interleaver), arearranged in the same RBs as shown in FIG. 26. Here, one of the two Nullsinserted in the block interleaver shown in FIG. 25 is inserted in the4-row×2-column first half of the block interleaver shown in FIG. 25comprising the first and second columns, and the other of the two Nullsis inserted in the 4-row×2-column second half of the block interleavercomprising the third and fourth columns. The positions at which the twoNulls are inserted are the second column of the fourth row of the firsthalf of block interleaver output (the second column of the fourth row ofthe block interleaver shown in FIG. 25), and the second column of thefourth row of the second half of block interleaver output (the fourthcolumn of the fourth row of the block interleaver shown in FIG. 25).That is to say, the two Nulls are inserted at the same positions in thefirst half and second half of the block interleaver shown in FIG. 25.That is to say, the two Nulls are inserted at positions that can bearranged in the same RB in the block interleaver. Consequently, for Dchchannel numbers input at positions other than positions at which a Nullis inserted, also, a correspondence relationship whereby channel numberswithin a predetermined number (number of columns/Nd) are arranged in thesame RB is maintained. Therefore, Dch's with channel numbers within apredetermined number (number of columns/Nd) are arranged in the same RBeven if the number of Dch channels is smaller than the size of the blockinterleaver.

Next, the input/output processing flow of the block interleaver shown inFIG. 25 will be described using FIG. 27. Here, the number of rows of theblock interleaver is fixed at 4.

In step (hereinafter referred to as “ST”) 101, the size of the blockinterleaver is decided as ceil(Nrb/4) rows×4 columns.

In ST102, it is determined whether or not number of RBs Nrb is divisibleby 4. Here, operator mod shown in FIG. 27 indicates a modulo operator.

If number of RBs Nrb is determined to be divisible by 4 in ST102 (ST102:YES), in ST103 Dch channel numbers (k) are written consecutively to theblock interleaver in the column direction.

In ST104, Dch channel numbers (j(k)) are read consecutively from theblock interleaver in the row direction.

On the other hand, if number of RBs Nrb is determined not to bedivisible by 4 in ST102 (ST102: NO), in ST105 Dch channel numbers (k)are written consecutively to the block interleaver in the columndirection, in the same way as in ST103. However, a Null is inserted inevery other column in the last row (for example, the fourth row shown inFIG. 25) of the block interleaver.

In ST106, Dch channel numbers (j(k)) are read consecutively from theblock interleaver in the row direction in the same way as in ST104.However Dch channel numbers (j(k)) are read in which Nulls inserted atthe time of block interleaver writing (for example, the second columnand fourth column of the fourth row shown in FIG. 25) are skipped.

Thus, if the number of Dch channels is not divisible by the number ofcolumns of the block interleaver, at the time of block interleaver inputDch channel numbers k are written with Nulls inserted, and at the timeof block interleaver output Dch channel numbers (k) are read with theNulls skipped. By this means, even if the number of Dch channels is notdivisible by the number of columns of the block interleaver, Dch's withconsecutive channel numbers can be arranged in different RBs, and Dch'swith channel numbers within a predetermined number can be arranged inone RB, in the same way as in Arrangement Method 3 of Embodiment 1.

In base station 100 and mobile station 200, Dch's with consecutivechannel numbers are arranged in different RBs by means of theabove-described Dch channel arrangement method, and RBs for which Dch'swith channel numbers within a predetermined number are arranged in oneRB, and Dch's, are mutually mapped in advance. That is to say,allocation section 103 of base station 100 (FIG. 1) and demappingsection 207 of mobile station 200 (FIG. 2) hold the Dch arrangementpattern shown in FIG. 26 associating RBs with Dch's.

Then, in the same way as in Arrangement Method 3 of Embodiment 1,allocation section 103 of base station 100 allocates a Dch data symbolto RBs in accordance with the Dch arrangement pattern shown in FIG. 26.On the other hand, demapping section 207 of mobile station 200,following a similar procedure to allocation section 103, extracts a Dchdata symbol addressed to that station from a plurality of RBs inaccordance with the Dch arrangement pattern shown in FIG. 26.

By this means, in the same way as in Arrangement Method 3 of Embodiment1, when the number of Dch's used for a Dch data symbol of one mobilestation is small, although there is a possibility of subblocks otherthan subblocks allocated within RBs not being used, a frequencydiversity effect can be obtained preferentially. Also, even when thenumber of Dch's used for a Dch data symbol of one mobile station islarge—that is, when the number of allocated RBs is large—it is possibleto use all subblocks within RBs while obtaining a frequency diversityeffect.

Thus, in this embodiment, by interleaving Dch channel numbers, Dch'swith consecutive channel numbers are arranged in different RBs, andDch's with channel numbers within a predetermined number are arranged inone RB. By this means, in the same way as in Arrangement Method 3 ofEmbodiment 1, when the number of Dch's used for a Dch data symbol of onemobile station is small, a frequency diversity effect can be improved.Also, even when the number of Dch's used for a Dch data symbol of onemobile station is large, a frequency diversity effect can be improvedwithout reducing communication resource utilization efficiency.

Also, in this embodiment, even if the number of Dch channels and thesize of the block interleaver do not match and the number of Dchchannels is not divisible by the number of columns of the blockinterleaver, Dch's with consecutive channel numbers can be arranged indifferent RBs, and Dch's with channel numbers within a predeterminednumber can be arranged in one RB, by inserting Nulls in the blockinterleaver. Furthermore, according to this embodiment, it is possibleto apply the same block interleaver configuration—that is, the samechannel arrangement method—to systems with different numbers of Dchchannels simply by inserting Nulls in the block interleaver.

In this embodiment, a case has been described in which number of RBs Nrbis an even number (for example, Nrb=14). However, the same kind ofeffect as in this embodiment can also be obtained when number of RBs Nrbis an odd number by replacing Nrb with the maximum even number notexceeding Nrb.

Also, in this embodiment, a case has been described in which positionsat which two Nulls are inserted are the second column of the fourth rowof the first half of block interleaver output (the second column of thefourth row of the block interleaver shown in FIG. 25), and the fourthcolumn of the fourth row of the second half of block interleaver output(the fourth column of the fourth row of the block interleaver shown inFIG. 25). However, in the present invention, it is only necessary forpositions at which two Nulls are inserted to be the same position in thefirst half and second half of block interleaver output. Thus, forexample, positions at which two Nulls are inserted may be the firstcolumn of the fourth row of the first half of block interleaver output(the first column of the fourth row of the block interleaver shown inFIG. 25), and the first column of the fourth row of the second half ofblock interleaver output (the third column of the fourth row of theblock interleaver shown in FIG. 25). Also, positions at which two Nullsare inserted are not limited to the last row of the block interleaver(for example, the fourth row shown in FIG. 25), but may be in adifferent row (for example, the first, second, or third row shown inFIG. 25).

This concludes a description of embodiments of the present invention.

In the above embodiments, a channel arrangement method whereby Dch's arearranged in RBs depends on a total number of RBs (Nrb) decided by thesystem bandwidth. Thus, provision may be made for a base station andmobile station to hold a Dch channel number/RB number correspondencetable (such as shown in FIG. 4, FIG. 8, FIG. 11, FIG. 15, or FIG. 26,for example) for each system bandwidth, and at the time of Dch datasymbol allocation, to reference a correspondence table corresponding toa system bandwidth to which a Dch data symbol is allocated.

In the above embodiments, a signal received by a base station (that is,a signal transmitted in an uplink by a mobile station) has beendescribed as being transmitted by means of an OFDM scheme, but thissignal may also be transmitted by means of a transmitting scheme otherthan an OFDM scheme, such as a single-carrier scheme or CDMA scheme, forexample.

In the above embodiments, a case has been described in which an RB iscomprised of a plurality of subcarriers comprised of an OFDM symbol, butthe present invention is not limited to this, and it is only necessaryfor a block to be comprised of consecutive frequencies.

In the above embodiments, a case has been described in which RBs arecomprised consecutively in the frequency domain, but RBs may also becomprised consecutively in the time domain.

In the above embodiments, cases have been described that apply to asignal transmitted by a base station (that is, a signal transmitted in adownlink by a base station), but the present invention may also beapplied to a signal received by a base station (that is, a signaltransmitted in an uplink by a mobile station). In this case, the basestation performs adaptive control of RB allocation and so forth for anuplink signal.

In the above embodiments, adaptive modulation is performed only for anLch, but adaptive modulation may also be similarly performed for a Dch.At this time, a base station may perform adaptive modulation for Dchdata based on total-band average received quality information reportedfrom each mobile station.

In the above embodiments, an RB used for a Dch has been described asbeing divided into a plurality of subblocks in the time domain, but anRB used for a Dch may also be divided into a plurality of subblocks inthe frequency domain, or may be divided into a plurality of subblocks inthe time domain and the frequency domain. That is to say, in one RB, aplurality of Dch's may be frequency-domain-multiplexed, or may betime-domain-multiplexed and frequency-domain-multiplexed.

In these embodiments, a case has been described in which, when aplurality of different Dch's with consecutive channel numbers areallocated to one mobile station, only a first channel number and lastchannel number are indicated to a mobile station from a base station,but, for example, a first channel number and a number of channels mayalso be indicated to a mobile station from a base station.

In these embodiments, a case has been described in which one Dch isarranged in RBs distributively arranged at equal intervals in thefrequency domain, but one Dch need not be arranged in RBs distributivelyarranged at equal intervals in the frequency domain.

In the above embodiments, a Dch has been used as a channel forperforming frequency diversity transmission, but a channel used is notlimited to a Dch, and need only be a channel that is distributivelyarranged in a plurality of RBs or a plurality of subcarriers in thefrequency domain, and enables a frequency diversity effect to beobtained. Also, an Lch has been used as a channel for performingfrequency scheduling transmission, but a channel used is not limited toan Lch, and need only be a channel that enables a multi-user diversityeffect to be obtained.

A Dch is also referred to as a DVRB (Distributed Virtual ResourceBlock), and an Lch is also referred to as an LVRB (Localized VirtualResource Block). Furthermore, an RB used for a Dch is also referred toas a DRB or DPRB (Distributed Physical Resource Block), and an RB usedfor an Lch is also referred to as an LRB or LPRB (Localized PhysicalResource Block).

A mobile station is also referred to as UE, a base station apparatus asNode B, and a subcarrier as a tone. An RB is also referred to as asubchannel, a subcarrier block, a subcarrier group, a subband, or achunk. A CP is also referred to as a Guard Interval (GI). A subframe isalso referred to as a slot or frame.

In the above embodiments, a case has been described by way of example inwhich the present invention is configured as hardware, but it is alsopossible for the present invention to be implemented by software.

The function blocks used in the descriptions of the above embodimentsare typically implemented as LSIs, which are integrated circuits. Thesemay be implemented individually as single chips, or a single chip mayincorporate some or all of them. Here, the term LSI has been used, butthe terms IC, system LSI, super LSI, and ultra LSI may also be usedaccording to differences in the degree of integration.

The method of implementing integrated circuitry is not limited to LSI,and implementation by means of dedicated circuitry or a general-purposeprocessor may also be used. An FPGA (Field Programmable Gate Array) forwhich programming is possible after LSI fabrication, or a reconfigurableprocessor allowing reconfiguration of circuit cell connections andsettings within an LSI, may also be used.

In the event of the introduction of an integrated circuit implementationtechnology whereby LSI is replaced by a different technology as anadvance in, or derivation from, semiconductor technology, integration ofthe function blocks may of course be performed using that technology.The application of biotechnology or the like is also a possibility.

The disclosures of Japanese Patent Application No. 2007-161958, filed onJun. 19, 2007, Japanese Patent Application No. 2007-211545, filed onAug. 14, 2007, and Japanese Patent Application No. 2008-056561, filed onMar. 6, 2008, including the specifications, drawings and abstracts, areincorporated herein by reference in their entirety.

INDUSTRIAL APPLICABILITY

The present invention is suitable for use in a mobile communicationsystem or the like.

1. A channel arrangement method wherein first arrangement is performedwhereby a plurality of subcarriers forming a multicarrier signal aredivided into a plurality of resource blocks, and a plurality ofdifferent distributed channels with consecutive channel numbers arearranged in one resource block.
 2. The channel arrangement methodaccording to claim 1, wherein second arrangement is further performedwhereby a distributed channel whose channel number is smallest orlargest among the plurality of distributed channels and a distributedchannel with a consecutive channel number are arranged in the oneresource block and a resource block distributively arranged in afrequency domain.
 3. The channel arrangement method according to claim1, wherein third arrangement is further performed whereby arrangement isperformed in order from resource blocks at both ends of a band in orderfrom a distributed channel with a small channel number among theplurality of distributed channels.
 4. The channel arrangement methodaccording to claim 1, wherein the plurality of distributed channels aretime-domain-multiplexed in the one resource block.
 5. The channelarrangement method according to claim 1, wherein the plurality ofdistributed channels are frequency-domain-multiplexed in the oneresource block.
 6. The channel arrangement method according to claim 1,wherein the plurality of different distributed channels with consecutivechannel numbers are allocated to a distributed symbol of one radiocommunication mobile station apparatus.
 7. The channel arrangementmethod according to claim 2, wherein switching is performed between thefirst arrangement and the second arrangement according to a number ofthe plurality of distributed channels arranged in the one resourceblock.
 8. The channel arrangement method according to claim 2, whereinswitching is performed between the first arrangement and the secondarrangement according to a state of a channel.
 9. The channelarrangement method according to claim 3, wherein switching is performedbetween the first arrangement and the third arrangement according to anumber of the plurality of distributed channels arranged in the oneresource block.
 10. A radio communication base station apparatus thattransmits a multicarrier signal composed of a plurality of subcarriersdivided into a plurality of resource blocks, the radio communicationbase station apparatus comprising: an allocation section that allocatesdata subject to frequency diversity transmission to a resource block inwhich a plurality of different distributed channels with consecutivechannel numbers are arranged; and a transmitting section that transmitsthe multicarrier signal to which the data has been allocated.